This invention relates generally to a stereoscopic display of images and related apparatus. More specifically the present invention is a system and method for 3-D visualization based on parallel information processing of stereo imaging on multi aspect displays.
Stereoscopic display of images has become increasingly important in modern times. For example, training of professionals, from pilots to physicians, now frequently relies upon the visualization of stereographic images. Further it is important that multiple aspects of an image be able to be viewed so that, for example, during simulations of examination of human or mechanical parts, a viewer can have a continuous stereoscopic view of those parts without having to change data or switch images.
Conventional stereoscopic display systems have been in use for many years. All of these rely upon segregating images for the right and left eyes. For example, an apparatus which sequentially displays different views to the left and right eye of a viewer has been used successfully in cartographic and other applications. In this instance, using stereo image alternation, a different view is sequentially presented to the left and right eye of the viewer. This is also accomplished by using cathode ray tubes or liquid crystal displays whereby a viewer wears special glasses such as polarizing glasses or liquid crystal shutter glasses in order to see a different image in the left and right eye.
Lenticular lenses have also been used to allow a viewer to see a left and right image separately when a viewer is at an optimum distance from the lenticular lens screen. For example U.S. Pat. No. 5,838,494 to Araki was issued for an xe2x80x9cApparatus for Displaying Image Allowing Observer to Recognize Stereoscopic Image.xe2x80x9d This apparatus uses a lenticular screen displaying a plurality of striped images each stripe corresponding to the parallax view of the left and right eye when the user is looking through the lenticular screen. This apparatus presents a limited number views of a stereo image pair and is therefore limited in the number of views that can be displayed.
U.S. Pat. No. 5,930,037 was issued to Imai for a xe2x80x9cStereoscopic Display Apparatus Which Prevents Inverse Stereoscopic Vision.xe2x80x9d This invention relates to the use of lenticular lenses to see stereoscopic image but also prevents the phenomenon known as inverse stereoscopic viewing when the right eye sees the image that is destined for the left eye and vice versa. While this does prevent a certain phenomena from occurring, this invention is limited in the number of stereoscopic image pairs that can be present to a particular user.
U.S. Pat. No. 5,712,732 was issued to Street for an xe2x80x9cAuto Stereoscopic Image Display Adjustable for Observer Location and Distance.xe2x80x9d This invention was created to account for the fact that, when a lenticular lens is used, a viewer must be at a particular distance from the lens in order for the lens to operate correctly. This invention comprises a distance measuring apparatus allowing a system to determine the position of the viewer""s head in terms of distance and position (left-right) relative to the screen. In this fashion an appropriate stereographic image pair can be presented to the user at any particular location. Again this invention relies upon a lenticular screen to separate the parallax views for the left and right eye of the viewer. The head location apparatus dictates various other geometries associated with viewing the stereographic pairs of an image. However, this invention relates to adapting for the location of the viewer""s head during such viewing and is limited in the number of aspects of images that can be created.
What would be desirable is a system that provides numerous aspects or xe2x80x9cmulti aspectxe2x80x9d display such that the user can see many aspects of a particular object when desired. It would further be useful for such viewing to take place in a flexible way so that the viewer is not constrained in terms of the location of the viewer""s head when seeing the stereo image.
It is therefore an objective of the present invention to provide for multi aspect image viewing to create a stereo image.
It is a further objective of the present invention to be able to present an unlimited number of aspects of an image to a viewer so as not to lose any information while simultaneously having a full stereo image presented to the viewer.
It is yet another objective of the present invention to simplify the three-dimensional (3-D) visualization of objects.
It is a further objective of the present invention to improve the perception of 3-D information to a viewer.
It is a further objective of the present invention to remove sources of error from the viewing of stereographic images.
It is yet another objective of the present invention to eliminate any mask or obstruction from the view of a viewer when reviewing stereo imagery.
It is yet another objective of the present invention to eliminate the parallax barrier from the view of viewers trying to visualize a three dimensional scene.
In conventional parallax barrier-type of lenticular lenses, very few aspects of a particular object are presented. Further, one screen, or plane, contains all of the information about the various aspects while the other screen (or mask) contains only the lenticular lens or running slit that isolates the left aspect from the right aspect of an image being viewed. Further, whenever a viewer uses a parallax barrier type of viewing system, the viewer is actually seeing the parallax barrier or the lenticular lens. This further limits the number of aspects of an image that can be seen by a viewer in attempting to view stereographic images.
The present invention is a system and method for three-dimensional visualization based upon parallel information processing of stereo and multi aspect images. The images can be processed for a single 3-D viewing zone or multiple 3-D viewing zones. Further, in another embodiment, the processing can be adaptive in nature so as to be continually processed as the location of the viewer changes. Thus the perception of 3-D images by the viewer is improved by not constraining the viewer in any meaningful way.
In the present invention, at least two transmissive electronic display screens are positioned one behind another. Each such screen is composed of multiple pixels or cells that collectively are capable of forming an image. Although the transmissive electronic display screens will be referred to hereinafter as LCDs (liquid crystal displays), the present invention is not meant to be limited to LCDs and can use other transmissive electronic display means, such as, but not limited to, plasma displays, OLED (organic light emitting diode) or OLEP (organic light emitting polymer) screens. The screens are transmissive, i.e. they each transmit light. An illumination means is positioned behind the screens to illuminate the LCD images created.
Unlike prior art systems that use a pair of screens to display a right and left stereographic image pair or aspect (hereafter called stereopair), each screen of the present invention displays a calculated image that is not one of the stereopair images, but is rather a derivitive of the stereopair images that interact in the present design to produce the stereo image to be viewed. The information is derived from the database of stereopairs stored in a memory unit. A memory unit provides a desired stereopair to the processing block, which in turn processes the calculated images to be displayed by the LCD panels. Further, the processing block can control the lighting unit that illuminates the LCD panels.
Since the 3-D image information is distributed between the LCD panels, there is no loss of resolution as found in prior art systems wherein both aspects must be displayed on a single screen or plane, such as with lenticular viewing systems.
In another embodiment of the invention, the calculated images are presented to the viewer based upon a sensing of the viewer position. This viewer position signal is input to the processing block by means known in the art, such as IR sensing of position or RF or ultrasonic tracking means, which in turn retrieves a different stereopair from the memory unit for subsequent processing, presentation, and display by the controller of the LCD panels.
In a basic embodiment of the invention, the calculated image in each panel acts as a mask for the other panel(s). Thus, the viewer sees no images other than the object itself. This in contrast to conventional parallax barrier-type imaging systems, where the mask can clearly be seen. In addition, this preliminary processing of the image results in the absence of noise and distortion of a visual nature such as that created by lenticular screens or lenses.
In another embodiment of the invention, a separate mask panel can be included between the LCD panels so as to increase the image quality and suppress Moirxc3xa9 patterns.